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Kon E, Cossard A, Jossin Y. Neuronal Polarity in the Embryonic Mammalian Cerebral Cortex. Front Cell Neurosci 2017; 11:163. [PMID: 28670267 PMCID: PMC5472699 DOI: 10.3389/fncel.2017.00163] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/26/2017] [Indexed: 11/13/2022] Open
Abstract
The cerebral cortex is composed of billions of neurons that can grossly be subdivided into two broad classes: inhibitory GABAergic interneurons and excitatory glutamatergic neurons. The majority of cortical neurons in mammals are the excitatory type and they are the main focus of this review article. Like many of the cells in multicellular organisms, fully differentiated neurons are both morphologically and functionally polarized. However, they go through several changes in polarity before reaching this final mature differentiated state. Neurons are derived from polarized neuronal progenitor/stem cells and their commitment to neuronal fate is decided by cellular and molecular asymmetry during their last division in the neurogenic zone. They migrate from their birthplace using so-called multipolar migration, during which they switch direction of movement several times, and repolarize for bipolar migration when the axon is specified. Therefore, neurons have to break their previous symmetry, change their morphology and adequately respond to polarizing signals during migration in order to reach the correct position in the cortex and start making connections. Finally, the dendritic tree is elaborated and the axon/dendrite morphological polarity is set. Here we will describe the function, establishment and maintenance of polarity during the different developmental steps starting from neural stem cell (NSC) division, neuronal migration and axon specification at embryonic developmental stages.
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Affiliation(s)
- Elif Kon
- Mammalian Development and Cell Biology Unit, Institute of Neuroscience, Université catholique de LouvainBrussels, Belgium
| | - Alexia Cossard
- Mammalian Development and Cell Biology Unit, Institute of Neuroscience, Université catholique de LouvainBrussels, Belgium
| | - Yves Jossin
- Mammalian Development and Cell Biology Unit, Institute of Neuroscience, Université catholique de LouvainBrussels, Belgium
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Lammert DB, Middleton FA, Pan J, Olson EC, Howell BW. The de novo autism spectrum disorder RELN R2290C mutation reduces Reelin secretion and increases protein disulfide isomerase expression. J Neurochem 2017; 142:89-102. [PMID: 28419454 DOI: 10.1111/jnc.14045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/22/2017] [Accepted: 04/05/2017] [Indexed: 12/11/2022]
Abstract
Despite the recent identification of over 40 missense heterozygous Reelin gene (RELN) mutations in autism spectrum disorder (ASD), none of these has been functionally characterized. Reelin is an integral signaling ligand for proper brain development and post-natal synapse function - properties likely disrupted in ASD patients. We find that the R2290C mutation, which arose de novo in an affected ASD proband, and other analogous mutations in arginine-amino acid-arginine domains reduce protein secretion. Closer analysis of RELN R2290C heterozygous neurospheres reveals up-regulation of Protein Disulfide Isomerase A1, best known as an endoplasmic reticulum-chaperone protein, which has been linked to neuronal pathology. This effect is recapitulated in a heterozygous RELN mouse mutant that is characterized by defective Reelin secretion. These findings suggest that both a deficiency in Reelin signaling and pathologic impairment of Reelin secretion may contribute to ASD risk.
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Affiliation(s)
- Dawn B Lammert
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Frank A Middleton
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Jen Pan
- The Broad Institute, Stanley Center Neurobiology, Cambridge, Massachusetts, USA
| | - Eric C Olson
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Brian W Howell
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
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53
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Alternative splicing as a regulator of development and tissue identity. Nat Rev Mol Cell Biol 2017; 18:437-451. [PMID: 28488700 DOI: 10.1038/nrm.2017.27] [Citation(s) in RCA: 755] [Impact Index Per Article: 107.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alternative splicing of eukaryotic transcripts is a mechanism that enables cells to generate vast protein diversity from a limited number of genes. The mechanisms and outcomes of alternative splicing of individual transcripts are relatively well understood, and recent efforts have been directed towards studying splicing networks. It has become apparent that coordinated splicing networks regulate tissue and organ development, and that alternative splicing has important physiological functions in different developmental processes in humans.
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Fyn regulates multipolar-bipolar transition and neurite morphogenesis of migrating neurons in the developing neocortex. Neuroscience 2017; 352:39-51. [PMID: 28363782 DOI: 10.1016/j.neuroscience.2017.03.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/07/2017] [Accepted: 03/20/2017] [Indexed: 01/03/2023]
Abstract
Fyn is a non-receptor protein tyrosine kinase that belongs to Src family kinases. Fyn plays a critical role in neuronal migration, but the mechanism remains unclear. Here, we reported that suppression of Fyn expression in mouse cerebral cortex led to migration defects of both early-born and late-born neurons. Morphological analysis showed that loss of Fyn function impaired multipolar-bipolar transition of newly generated neurons and neurite formation in the early phase of migration. Moreover, Fyn inhibition increased the length of leading process and decreased the branching number of the migrating cortical neurons. Together, these results indicate that Fyn controls neuronal migration by regulating the cytoskeletal dynamics and multipolar-bipolar transition of newly generated neurons during cortical development.
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55
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Dillon GM, Tyler WA, Omuro KC, Kambouris J, Tyminski C, Henry S, Haydar TF, Beffert U, Ho A. CLASP2 Links Reelin to the Cytoskeleton during Neocortical Development. Neuron 2017; 93:1344-1358.e5. [PMID: 28285824 PMCID: PMC5405870 DOI: 10.1016/j.neuron.2017.02.039] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 01/06/2017] [Accepted: 02/21/2017] [Indexed: 12/14/2022]
Abstract
The Reelin signaling pathway plays a crucial role in regulating neocortical development. However, little is known about how Reelin controls the cytoskeleton during neuronal migration. Here, we identify CLASP2 as a key cytoskeletal effector in the Reelin signaling pathway. We demonstrate that CLASP2 has distinct roles during neocortical development regulating neuron production and controlling neuron migration, polarity, and morphogenesis. We found downregulation of CLASP2 in migrating neurons leads to mislocalized cells in deeper cortical layers, abnormal positioning of the centrosome-Golgi complex, and aberrant length/orientation of the leading process. We discovered that Reelin regulates several phosphorylation sites within the positively charged serine/arginine-rich region that constitute consensus GSK3β phosphorylation motifs of CLASP2. Furthermore, phosphorylation of CLASP2 regulates its interaction with the Reelin adaptor Dab1 and this association is required for CLASP2 effects on neurite extension and motility. Together, our data reveal that CLASP2 is an essential Reelin effector orchestrating cytoskeleton dynamics during brain development.
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Affiliation(s)
- Gregory M Dillon
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
| | - William A Tyler
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Kerilyn C Omuro
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
| | - John Kambouris
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
| | - Camila Tyminski
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
| | - Shawna Henry
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
| | - Tarik F Haydar
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Uwe Beffert
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA.
| | - Angela Ho
- Department of Biology, Boston University, 24 Cummington Mall, Boston, MA 02215, USA.
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56
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Lane-Donovan C, Herz J. The ApoE receptors Vldlr and Apoer2 in central nervous system function and disease. J Lipid Res 2017; 58:1036-1043. [PMID: 28292942 DOI: 10.1194/jlr.r075507] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/08/2017] [Indexed: 01/17/2023] Open
Abstract
The LDL receptor (LDLR) family has long been studied for its role in cholesterol transport and metabolism; however, the identification of ApoE4, an LDLR ligand, as a genetic risk factor for late-onset Alzheimer's disease has focused attention on the role this receptor family plays in the CNS. Surprisingly, it was discovered that two LDLR family members, ApoE receptor 2 (Apoer2) and VLDL receptor (Vldlr), play key roles in brain development and adult synaptic plasticity, primarily by mediating Reelin signaling. This review focuses on Apoer2 and Vldlr signaling in the CNS and its role in human disease.
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Affiliation(s)
- Courtney Lane-Donovan
- Departments of Molecular Genetics and Neuroscience and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Joachim Herz
- Departments of Molecular Genetics and Neuroscience and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390 .,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390
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57
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Reelin transiently promotes N-cadherin-dependent neuronal adhesion during mouse cortical development. Proc Natl Acad Sci U S A 2017; 114:2048-2053. [PMID: 28174271 DOI: 10.1073/pnas.1615215114] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Reelin is an essential glycoprotein for the establishment of the highly organized six-layered structure of neurons of the mammalian neocortex. Although the role of Reelin in the control of neuronal migration has been extensively studied at the molecular level, the mechanisms underlying Reelin-dependent neuronal layer organization are not yet fully understood. In this study, we directly showed that Reelin promotes adhesion among dissociated neocortical neurons in culture. The Reelin-mediated neuronal aggregation occurs in an N-cadherin-dependent manner, both in vivo and in vitro. Unexpectedly, however, in a rotation culture of dissociated neocortical cells that gradually reaggregated over time, we found that it was the neural progenitor cells [radial glial cells (RGCs)], rather than the neurons, that tended to form clusters in the presence of Reelin. Mathematical modeling suggested that this clustering of RGCs could be recapitulated if the Reelin-dependent promotion of neuronal adhesion were to occur only transiently. Thus, we directly measured the adhesive force between neurons and N-cadherin by atomic force microscopy, and found that Reelin indeed enhanced the adhesiveness of neurons to N-cadherin; this enhanced adhesiveness began to be observed at 30 min after Reelin stimulation, but declined by 3 h. These results suggest that Reelin transiently (and not persistently) promotes N-cadherin-mediated neuronal aggregation. When N-cadherin and stabilized β-catenin were overexpressed in the migrating neurons, the transfected neurons were abnormally distributed in the superficial region of the neocortex, suggesting that appropriate regulation of N-cadherin-mediated adhesion is important for correct positioning of the neurons during neocortical development.
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58
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Ishii K, Kubo KI, Nakajima K. Reelin and Neuropsychiatric Disorders. Front Cell Neurosci 2016; 10:229. [PMID: 27803648 PMCID: PMC5067484 DOI: 10.3389/fncel.2016.00229] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/22/2016] [Indexed: 12/22/2022] Open
Abstract
Proper neuronal migration and laminar formation during corticogenesis is essential for normal brain function. Disruption of these developmental processes is thought to be involved in the pathogenesis of some neuropsychiatric conditions. Especially, Reelin, a glycoprotein mainly secreted by the Cajal-Retzius cells and a subpopulation of GABAergic interneurons, has been shown to play a critical role, both during embryonic and postnatal periods. Indeed, animal studies have clearly revealed that Reelin is an essential molecule for proper migration of cortical neurons and finally regulates the cell positioning in the cortex during embryonic and early postnatal stages; by contrast, Reelin signaling is closely involved in synaptic function in adulthood. In humans, genetic studies have shown that the reelin gene (RELN) is associated with a number of psychiatric diseases, including Schizophrenia (SZ), bipolar disorder (BP) and autistic spectrum disorder. Indeed, Reln haploinsufficiency has been shown to cause cognitive impairment in rodents, suggesting the expression level of the Reelin protein is closely related to the higher brain functions. However, the molecular abnormalities in the Reelin pathway involved in the pathogenesis of psychiatric disorders are not yet fully understood. In this article, we review the current progress in the understanding of the Reelin functions that could be related to the pathogenesis of psychiatric disorders. Furthermore, we discuss the basis for selecting Reelin and molecules in its downstream signaling pathway as potential therapeutic targets for psychiatric illnesses.
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Affiliation(s)
- Kazuhiro Ishii
- Department of Anatomy, Keio University School of Medicine Tokyo, Japan
| | - Ken-Ichiro Kubo
- Department of Anatomy, Keio University School of Medicine Tokyo, Japan
| | - Kazunori Nakajima
- Department of Anatomy, Keio University School of Medicine Tokyo, Japan
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59
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Wang W, Moerman-Herzog AM, Slaton A, Barger SW. Presenilin 1 mutations influence processing and trafficking of the ApoE receptor apoER2. Neurobiol Aging 2016; 49:145-153. [PMID: 27810638 DOI: 10.1016/j.neurobiolaging.2016.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/15/2022]
Abstract
Presenilin (PS)-1 is an intramembrane protease serving as the catalytic component of γ-secretase. Mutations in the PS1 gene are the most common cause of familial Alzheimer's disease (FAD). The low-density lipoprotein (LDL)-receptor family member apoER2 is a γ-secretase substrate that has been associated with AD in several ways, including acting as a receptor for apolipoprotein E (ApoE). ApoER2 is processed by γ-secretase into a C-terminal fragment (γ-CTF) that appears to regulate gene expression. FAD PS1 mutations were tested for effects on apoER2. PS1 mutation R278I showed impaired γ-secretase activity for apoER2 in the basal state or after exposure to Reelin. PS1 M146V mutation permitted accumulation of apoER2 CTFs after Reelin treatment, whereas no difference was seen between wild-type (WT) and M146V in the basal state. PS1 L282V mutation, combined with the γ-secretase inhibitor N-(N-[3,5-Difluorophenacetyl]-L-alanyl)-S-phenylglycine t-butyl ester, greatly reduced the cell-surface levels of apoER2 without affecting total apoER2 levels, suggesting a defect in receptor trafficking. These findings indicate that impaired processing or localization of apoER2 may contribute to the pathogenic effects of FAD mutations in PS1.
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Affiliation(s)
- Wei Wang
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | - Arthur Slaton
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Steven W Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Geriatrics Research, Education and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, AR, USA.
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60
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Mata A, Urrea L, Vilches S, Llorens F, Thüne K, Espinosa JC, Andréoletti O, Sevillano AM, Torres JM, Requena JR, Zerr I, Ferrer I, Gavín R, Del Río JA. Reelin Expression in Creutzfeldt-Jakob Disease and Experimental Models of Transmissible Spongiform Encephalopathies. Mol Neurobiol 2016; 54:6412-6425. [PMID: 27726110 DOI: 10.1007/s12035-016-0177-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/28/2016] [Indexed: 12/22/2022]
Abstract
Reelin is an extracellular glycoprotein involved in key cellular processes in developing and adult nervous system, including regulation of neuronal migration, synapse formation, and plasticity. Most of these roles are mediated by the intracellular phosphorylation of disabled-1 (Dab1), an intracellular adaptor molecule, in turn mediated by binding Reelin to its receptors. Altered expression and glycosylation patterns of Reelin in cerebrospinal and cortical extracts have been reported in Alzheimer's disease. However, putative changes in Reelin are not described in natural prionopathies or experimental models of prion infection or toxicity. With this is mind, in the present study, we determined that Reelin protein and mRNA levels increased in CJD human samples and in mouse models of human prion disease in contrast to murine models of prion infection. However, changes in Reelin expression appeared only at late terminal stages of the disease, which prevent their use as an efficient diagnostic biomarker. In addition, increased Reelin in CJD and in in vitro models does not correlate with Dab1 phosphorylation, indicating failure in its intracellular signaling. Overall, these findings widen our understanding of the putative changes of Reelin in neurodegeneration.
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Affiliation(s)
- Agata Mata
- Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Baldiri Reixac 15-21, 08028, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Laura Urrea
- Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Baldiri Reixac 15-21, 08028, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Silvia Vilches
- Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Baldiri Reixac 15-21, 08028, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Franc Llorens
- Department of Neurology, German Center for Neurodegenerative Diseases - DZNE, Universitätsmedizin Göttingen, Bonn, Germany
| | - Katrin Thüne
- Department of Neurology, German Center for Neurodegenerative Diseases - DZNE, Universitätsmedizin Göttingen, Bonn, Germany
| | - Juan-Carlos Espinosa
- Centro de Investigación en Sanidad Animal (CISA-INIA), Madrid, Valdeolmos, Spain
| | - Olivier Andréoletti
- UMR INRA ENVT 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076, Toulouse, France
| | - Alejandro M Sevillano
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, 15782, Santiago de Compostela, Spain
- Department of Medicine, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Juan María Torres
- Centro de Investigación en Sanidad Animal (CISA-INIA), Madrid, Valdeolmos, Spain
| | - Jesús Rodríguez Requena
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, 15782, Santiago de Compostela, Spain
- Department of Medicine, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Inga Zerr
- Department of Neurology, German Center for Neurodegenerative Diseases - DZNE, Universitätsmedizin Göttingen, Bonn, Germany
| | - Isidro Ferrer
- Institut de Neuropatologia, IDIBELL-Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Rosalina Gavín
- Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Baldiri Reixac 15-21, 08028, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - José Antonio Del Río
- Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Baldiri Reixac 15-21, 08028, Barcelona, Spain.
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, Barcelona, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain.
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain.
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61
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The Effects of Alpha Boswellic Acid on Reelin Expression and Tau Phosphorylation in Human Astrocytes. Neuromolecular Med 2016; 19:136-146. [PMID: 27567921 DOI: 10.1007/s12017-016-8437-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 08/16/2016] [Indexed: 10/21/2022]
Abstract
Reelin is an extracellular glycoprotein which contributes to synaptic plasticity and function of memory in the adult brain. It has been indicated that the Reelin signaling cascade participates in Alzheimer's disease (AD). Besides the neurons, glial cells such as astrocytes also express Reelin protein. While functional loss of astrocytes has been reported to be associated with AD, dysfunction of astrocytic Reelin signaling pathway has not received much attention. Therefore, we investigated the effects of α-boswellic acid (ABA) as one of the major component of Boswellia serrata resin on primary fetal human astrocytes under a stress paradigm as a possible model for AD through study on Reelin cascade. For this aim, we used streptozotocin (STZ), in which from an outlook generates Alzheimer's hallmarks in astrocytes, and assayed Reelin expression, Tau and Akt phosphorylation as well as reactive oxygen species (ROS) generation and apoptosis in the presences of ABA. Our results indicated that while STZ (100 µM) down-regulated the expression of Reelin, ABA (25 µM) up-regulated its expression (p < 0.01) for 24 h. ABA efficiently reduced hyperphosphorylated Tau (Ser404) in STZ-treated astrocytes (p < 0.01). Furthermore, STZ-induced apoptosis by increasing cleaved caspase three (p < 0.01) and ROS generation (p < 0.01), a further pathological hallmark of Tauopathy. On the other hand, ABA decreased ROS generation and promoted proliferation of astrocytes through elevating Survivin expression (p < 0.01). These results showed that ABA could be considered as a potent therapeutic agent for prevention and decreasing the progression of Alzheimer's hallmarks in astrocytes; however, more in vivo studies would be needed.
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Cuchillo-Ibañez I, Mata-Balaguer T, Balmaceda V, Arranz JJ, Nimpf J, Sáez-Valero J. The β-amyloid peptide compromises Reelin signaling in Alzheimer's disease. Sci Rep 2016; 6:31646. [PMID: 27531658 PMCID: PMC4987719 DOI: 10.1038/srep31646] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/21/2016] [Indexed: 12/13/2022] Open
Abstract
Reelin is a signaling protein that plays a crucial role in synaptic function, which expression is influenced by β-amyloid (Aβ). We show that Reelin and Aβ oligomers co-immunoprecipitated in human brain extracts and were present in the same size-exclusion chromatography fractions. Aβ treatment of cells led to increase expression of Reelin, but secreted Reelin results trapped together with Aβ aggregates. In frontal cortex extracts an increase in Reelin mRNA, and in soluble and insoluble (guanidine-extractable) Reelin protein, was associated with late Braak stages of Alzheimer's disease (AD), while expression of its receptor, ApoER2, did not change. However, Reelin-dependent induction of Dab1 phosphorylation appeared reduced in AD. In cells, Aβ reduced the capacity of Reelin to induce internalization of biotinylated ApoER2 and ApoER2 processing. Soluble proteolytic fragments of ApoER2 generated after Reelin binding can be detected in cerebrospinal fluid (CSF). Quantification of these soluble fragments in CSF could be a tool to evaluate the efficiency of Reelin signaling in the brain. These CSF-ApoER2 fragments correlated with Reelin levels only in control subjects, not in AD, where these fragments diminished. We conclude that while Reelin expression is enhanced in the Alzheimer's brain, the interaction of Reelin with Aβ hinders its biological activity.
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Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Valeria Balmaceda
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Juan José Arranz
- Departamento Producción Animal, Universidad de León, León, Spain
| | - Johannes Nimpf
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, E-03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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63
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Bock HH, May P. Canonical and Non-canonical Reelin Signaling. Front Cell Neurosci 2016; 10:166. [PMID: 27445693 PMCID: PMC4928174 DOI: 10.3389/fncel.2016.00166] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/08/2016] [Indexed: 12/11/2022] Open
Abstract
Reelin is a large secreted glycoprotein that is essential for correct neuronal positioning during neurodevelopment and is important for synaptic plasticity in the mature brain. Moreover, Reelin is expressed in many extraneuronal tissues; yet the roles of peripheral Reelin are largely unknown. In the brain, many of Reelin's functions are mediated by a molecular signaling cascade that involves two lipoprotein receptors, apolipoprotein E receptor-2 (Apoer2) and very low density-lipoprotein receptor (Vldlr), the neuronal phosphoprotein Disabled-1 (Dab1), and members of the Src family of protein tyrosine kinases as crucial elements. This core signaling pathway in turn modulates the activity of adaptor proteins and downstream protein kinase cascades, many of which target the neuronal cytoskeleton. However, additional Reelin-binding receptors have been postulated or described, either as coreceptors that are essential for the activation of the "canonical" Reelin signaling cascade involving Apoer2/Vldlr and Dab1, or as receptors that activate alternative or additional signaling pathways. Here we will give an overview of canonical and alternative Reelin signaling pathways, molecular mechanisms involved, and their potential physiological roles in the context of different biological settings.
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Affiliation(s)
- Hans H Bock
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf Düsseldorf, Germany
| | - Petra May
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf Düsseldorf, Germany
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Bosch C, Muhaisen A, Pujadas L, Soriano E, Martínez A. Reelin Exerts Structural, Biochemical and Transcriptional Regulation Over Presynaptic and Postsynaptic Elements in the Adult Hippocampus. Front Cell Neurosci 2016; 10:138. [PMID: 27303269 PMCID: PMC4884741 DOI: 10.3389/fncel.2016.00138] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/10/2016] [Indexed: 11/13/2022] Open
Abstract
Reelin regulates neuronal positioning and synaptogenesis in the developing brain, and adult brain plasticity. Here we used transgenic mice overexpressing Reelin (Reelin-OE mice) to perform a comprehensive dissection of the effects of this protein on the structural and biochemical features of dendritic spines and axon terminals in the adult hippocampus. Electron microscopy (EM) revealed both higher density of synapses and structural complexity of both pre- and postsynaptic elements in transgenic mice than in WT mice. Dendritic spines had larger spine apparatuses, which correlated with a redistribution of Synaptopodin. Most of the changes observed in Reelin-OE mice were reversible after blockade of transgene expression, thus supporting the specificity of the observed phenotypes. Western blot and transcriptional analyses did not show major changes in the expression of pre- or postsynaptic proteins, including SNARE proteins, glutamate receptors, and scaffolding and signaling proteins. However, EM immunogold assays revealed that the NMDA receptor subunits NR2a and NR2b, and p-Cofilin showed a redistribution from synaptic to extrasynaptic pools. Taken together with previous studies, the present results suggest that Reelin regulates the structural and biochemical properties of adult hippocampal synapses by increasing their density and morphological complexity and by modifying the distribution and trafficking of major glutamatergic components.
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Affiliation(s)
- Carles Bosch
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of BarcelonaBarcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), MadridSpain; Vall d'Hebron Institut de RecercaBarcelona, Spain
| | - Ashraf Muhaisen
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of BarcelonaBarcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), MadridSpain; Vall d'Hebron Institut de RecercaBarcelona, Spain; Institute of Neurosciences, University of BarcelonaBarcelona, Spain
| | - Lluís Pujadas
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of BarcelonaBarcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), MadridSpain; Vall d'Hebron Institut de RecercaBarcelona, Spain
| | - Eduardo Soriano
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of BarcelonaBarcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), MadridSpain; Vall d'Hebron Institut de RecercaBarcelona, Spain; Institute of Neurosciences, University of BarcelonaBarcelona, Spain; Institució Catalana de Recerca i Estudis Avançats AcademiaBarcelona, Spain
| | - Albert Martínez
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona Barcelona, Spain
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Cuchillo-Ibañez I, Balmaceda V, Mata-Balaguer T, Lopez-Font I, Sáez-Valero J. Reelin in Alzheimer’s Disease, Increased Levels but Impaired Signaling: When More is Less. J Alzheimers Dis 2016; 52:403-16. [DOI: 10.3233/jad-151193] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Valeria Balmaceda
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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Lee GH, D'Arcangelo G. New Insights into Reelin-Mediated Signaling Pathways. Front Cell Neurosci 2016; 10:122. [PMID: 27242434 PMCID: PMC4860420 DOI: 10.3389/fncel.2016.00122] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 04/27/2016] [Indexed: 11/21/2022] Open
Abstract
Reelin, a multifunctional extracellular protein that is important for mammalian brain development and function, is secreted by different cell types in the prenatal or postnatal brain. The spatiotemporal regulation of Reelin expression and distribution during development relates to its multifaceted function in the brain. Prenatally Reelin controls neuronal radial migration and proper positioning in cortical layers, whereas postnatally Reelin promotes neuronal maturation, synaptic formation and plasticity. The molecular mechanisms underlying the distinct biological functions of Reelin during and after brain development involve unique and overlapping signaling pathways that are activated following Reelin binding to its cell surface receptors. Distinct Reelin ligand isoforms, such as the full-length protein or fragments generated by proteolytic cleavage differentially affect the activity of downstream signaling pathways. In this review, we discuss recent advances in our understanding of the signaling transduction pathways activated by Reelin that regulate different aspects of brain development and function. A core signaling machinery, including ApoER2/VLDLR receptors, Src/Fyn kinases, and the adaptor protein Dab1, participates in all known aspects of Reelin biology. However, distinct downstream mechanisms, such as the Crk/Rap1 pathway and cell adhesion molecules, play crucial roles in the control of neuronal migration, whereas the PI3K/Akt/mTOR pathway appears to be more important for dendrite and spine development. Finally, the NMDA receptor (NMDAR) and an unidentified receptor contribute to the activation of the MEK/Erk1/2 pathway leading to the upregulation of genes involved in synaptic plasticity and learning. This knowledge may provide new insight into neurodevelopmental or neurodegenerative disorders that are associated with Reelin dysfunction.
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Affiliation(s)
- Gum Hwa Lee
- College of Pharmacy, Chosun University Gwangju, South Korea
| | - Gabriella D'Arcangelo
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey Piscataway, NJ, USA
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Lussier AL, Weeber EJ, Rebeck GW. Reelin Proteolysis Affects Signaling Related to Normal Synapse Function and Neurodegeneration. Front Cell Neurosci 2016; 10:75. [PMID: 27065802 PMCID: PMC4809875 DOI: 10.3389/fncel.2016.00075] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 03/11/2016] [Indexed: 01/13/2023] Open
Abstract
Reelin is a neurodevelopmental protein important in adult synaptic plasticity and learning and memory. Recent evidence points to the importance for Reelin proteolysis in normal signaling and in cognitive function. Support for the dysfunction of Reelin proteolysis in neurodegeneration and cognitive dysfunction comes from postmortem analysis of Alzheimer’s diseases (AD) tissues including cerebral spinal fluid (CSF), showing that levels of Reelin fragments are altered in AD compared to control. Potential key proteases involved in Reelin proteolysis have recently been defined, identifying processes that could be altered in neurodegeneration. Introduction of full-length Reelin and its proteolytic fragments into several mouse models of neurodegeneration and neuropsychiatric disorders quickly promote learning and memory. These findings support a role for Reelin in learning and memory and suggest further understanding of these processes are important to harness the potential of this pathway in treating cognitive symptoms in neuropsychiatric and neurodegenerative diseases.
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Affiliation(s)
- April L Lussier
- Department of Molecular Pharmacology and Physiology, USF Health Byrd Alzheimer's Disease Institute, University of South Florida Tampa, FL, USA
| | - Edwin J Weeber
- Department of Molecular Pharmacology and Physiology, USF Health Byrd Alzheimer's Disease Institute, University of South Florida Tampa, FL, USA
| | - G William Rebeck
- Department of Neuroscience, Georgetown University Washington, DC, USA
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Ding Y, Huang L, Xian X, Yuhanna IS, Wasser CR, Frotscher M, Mineo C, Shaul PW, Herz J. Loss of Reelin protects against atherosclerosis by reducing leukocyte-endothelial cell adhesion and lesion macrophage accumulation. Sci Signal 2016; 9:ra29. [PMID: 26980442 DOI: 10.1126/scisignal.aad5578] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The multimodular glycoprotein Reelin controls neuronal migration and synaptic transmission by binding to apolipoprotein E receptor 2 (Apoer2) and very low density lipoprotein receptor (Vldlr) on neurons. In the periphery, Reelin is produced by the liver, circulates in blood, and promotes thrombosis and hemostasis. To investigate if Reelin influences atherogenesis, we studied atherosclerosis-prone low-density lipoprotein receptor-deficient (Ldlr(-/-)) mice in which we inducibly deleted Reelin either ubiquitously or only in the liver, thus preventing the production of circulating Reelin. In both types of Reelin-deficient mice, atherosclerosis progression was markedly attenuated, and macrophage content and endothelial cell staining for vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were reduced at the sites of atherosclerotic lesions. Intravital microscopy revealed decreased leukocyte-endothelial adhesion in the Reelin-deficient mice. In cultured human endothelial cells, Reelin enhanced monocyte adhesion and increased ICAM1, VCAM1, and E-selectin expression by suppressing endothelial nitric oxide synthase (eNOS) activity and increasing nuclear factor κB (NF-κB) activity in an Apoer2-dependent manner. These findings suggest that circulating Reelin promotes atherosclerosis by increasing vascular inflammation, and that reducing or inhibiting circulating Reelin may present a novel approach for the prevention of cardiovascular disease.
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Affiliation(s)
- Yinyuan Ding
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX 75390, USA. Key Laboratory of Medical Electrophysiology, Ministry of Education of China, and the Institute of Cardiovascular Research, Sichuan Medical University, Luzhou 646000, China
| | - Linzhang Huang
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xunde Xian
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ivan S Yuhanna
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Frotscher
- Zentrum für Molekulare Neurobiologie Hamburg, Falkenried 94, 20251 Hamburg, Germany
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, 79104 Freiburg, Germany.
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Kwon HJ, Jang WC, Lim MH. Association between RELN Gene Polymorphisms and Attention Deficit Hyperactivity Disorder in Korean Children. Psychiatry Investig 2016; 13:210-6. [PMID: 27081382 PMCID: PMC4823197 DOI: 10.4306/pi.2016.13.2.210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Attention deficit hyperactivity disorder (ADHD) is common disorder of the school-age population. ADHD is familial and genetic studies estimate heritability at 80-90%. The aim of the present study was to investigate the association between the genetic type and alleles for RELNgene (rs736707, rs2229864, rs362746, rs362726, rs362691, rs1062831, rs607755, and rs2072403) in Korean children with ADHD. METHODS The sample consisted of 180 ADHD children and 159 control children. We diagnosed ADHD according to DSM-IV. ADHD symptoms were evaluated with Conners' Parent Rating Scales and Dupaul Parent ADHD Rating Scales. Blood samples were taken from the 339 subjects, DNA was extracted from blood lymphocytes, and PCR was performed for RELN Polymorphism. Alleles and genotype frequencies were compared using the chi-square test. We compared the allele and genotype frequencies of RELN gene polymorphism in the ADHD and control groups. RESULTS This study showed that there was a significant correlation among the frequencies of the rs736707 (OR=1.40, 95% CI=1.03-1.90, p=0.031) of alleles of RELN, but the final conclusions are not definite. CONCLUSION Follow up studies with larger patient or pure subgroups are expected. These results suggested that RELN might be related to ADHD symptoms.
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Affiliation(s)
- Ho Jang Kwon
- Environmental Health Center, Dankook Medical Hospital, Cheonan, Republic of Korea
- Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan, Republic of Korea
| | - Won-Cheol Jang
- Department of Chemistry, College of Natural Science, Dankook University, Cheonan, Republic of Korea
| | - Myung Ho Lim
- Environmental Health Center, Dankook Medical Hospital, Cheonan, Republic of Korea
- Department of Psychology, College of Public Welfare, Dankook University, Cheonan, Republic of Korea
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71
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Drago A, Crisafulli C, Sidoti A, Calabrò M, Serretti A. The microtubule-associated molecular pathways may be genetically disrupted in patients with Bipolar Disorder. Insights from the molecular cascades. J Affect Disord 2016; 190:429-438. [PMID: 26551401 DOI: 10.1016/j.jad.2015.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 09/24/2015] [Accepted: 10/10/2015] [Indexed: 01/15/2023]
Abstract
Bipolar Disorder is a severe disease characterized by pathological mood swings from major depressive episodes to manic ones and vice versa. The biological underpinnings of Bipolar Disorder have yet to be defined. As a consequence, pharmacological treatments are suboptimal. In the present paper we test the hypothesis that the molecular pathways involved with the direct targets of lithium, hold significantly more genetic variations associated with BD. A molecular pathway approach finds its rationale in the polygenic nature of the disease. The pathways were tested in a sample of ∼ 7,000 patients and controls. Data are available from the public NIMH database. The definition of the pathways was conducted according to the National Cancer Institute (http://pid.nci.nih.gov/). As a result, 3 out of the 18 tested pathways related to lithium action resisted the permutation analysis and were found to be associated with BD. These pathways were related to Reelin, Integrins and Aurora. A pool of genes selected from the ones linked with the above pathways was further investigated in order to identify the fine molecular mechanics shared by our significant pathways and also their link with lithium mechanism of action. The data obtained point out to a possible involvement of microtubule-related mechanics.
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Affiliation(s)
- Antonio Drago
- Department of Biomedical and Neuromotor Sciences - DIBINEM - University of Bologna, Bologna, Italy
| | - Concetta Crisafulli
- Department of Biomedical Science and Morphological and Functional Images, University of Messina, Via Consolare Valeria, 98125 Messina, Italy.
| | - Antonina Sidoti
- Department of Biomedical Science and Morphological and Functional Images, University of Messina, Via Consolare Valeria, 98125 Messina, Italy
| | - Marco Calabrò
- Department of Biomedical Science and Morphological and Functional Images, University of Messina, Via Consolare Valeria, 98125 Messina, Italy
| | - Alessandro Serretti
- Department of Biomedical and Neuromotor Sciences - DIBINEM - University of Bologna, Bologna, Italy
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72
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The Role of Reelin Signaling in Alzheimer’s Disease. Mol Neurobiol 2015; 53:5692-700. [DOI: 10.1007/s12035-015-9459-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/25/2015] [Indexed: 12/23/2022]
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AKT-independent Reelin signaling requires interactions of heterotrimeric Go and Src. Biochem Biophys Res Commun 2015; 467:1063-9. [PMID: 26441085 DOI: 10.1016/j.bbrc.2015.09.167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 09/30/2015] [Indexed: 11/23/2022]
Abstract
Reelin, a large secreted extracellular matrix glycoprotein, plays a key role in neuronal migration during cortical development and promotes neuronal maturation. The signaling pathway regulating neuronal maturation in the postnatal period are relatively less well understood. In this study, we demonstrated that a heterotrimeric G protein, Go, is a novel target of Reelin-induced signaling to promote neurite outgrowth. In primary hippocampal neurons of Reelin-deficient reeler mice, neurite outgrowth was significantly reduced and rescued upon addition of Reelin. Pertussis toxin (PTX) treatment or transfection with Gαo-siRNA suppressed Reelin-mediated neurite outgrowth in wild-type neurons. Additionally, Reelin treatment led to increased phosphorylation of AKT, GSK3β, and JNK, which were all effectively blocked by the PI3K inhibitor, LY294002. By comparison, PTX specifically blocked JNK activation, but not AKT and GSK3β. Immunoprecipitation assays disclosed that Reelin increases the active forms of both Src and Gαo and promotes their direct association. Notably, Dab1, a cytoplasmic adaptor molecule that mediates Reelin signaling, did not interact with Gαo. Neurite outgrowth by Reelin was induced via activating Src kinase, which directly stimulated Gαo, activity, leading to JNK activation. Based on the collective findings, we suggest that Reelin-dependent signaling mechanisms may be split into Src-AKT-dependent and Src-Go-dependent pathways. Our results additionally provide evidence that Reelin receptors cross-communicate with heterologous G protein-coupled receptors (GPCR) independently of the cognate ligands of GPCR.
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Lane-Donovan C, Philips GT, Wasser CR, Durakoglugil MS, Masiulis I, Upadhaya A, Pohlkamp T, Coskun C, Kotti T, Steller L, Hammer RE, Frotscher M, Bock HH, Herz J. Reelin protects against amyloid β toxicity in vivo. Sci Signal 2015; 8:ra67. [PMID: 26152694 DOI: 10.1126/scisignal.aaa6674] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a currently incurable neurodegenerative disorder and is the most common form of dementia in people over the age of 65 years. The predominant genetic risk factor for AD is the ε4 allele encoding apolipoprotein E (ApoE4). The secreted glycoprotein Reelin enhances synaptic plasticity by binding to the multifunctional ApoE receptors apolipoprotein E receptor 2 (Apoer2) and very low density lipoprotein receptor (Vldlr). We have previously shown that the presence of ApoE4 renders neurons unresponsive to Reelin by impairing the recycling of the receptors, thereby decreasing its protective effects against amyloid β (Aβ) oligomer-induced synaptic toxicity in vitro. We showed that when Reelin was knocked out in adult mice, these mice behaved normally without overt learning or memory deficits. However, they were strikingly sensitive to amyloid-induced synaptic suppression and had profound memory and learning disabilities with very low amounts of amyloid deposition. Our findings highlight the physiological importance of Reelin in protecting the brain against Aβ-induced synaptic dysfunction and memory impairment.
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Affiliation(s)
- Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Gary T Philips
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Murat S Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Irene Masiulis
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ajeet Upadhaya
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg 79085, Germany
| | - Cagil Coskun
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tiina Kotti
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Laura Steller
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg 20251, Germany
| | - Robert E Hammer
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg 20251, Germany
| | - Hans H Bock
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, Düsseldorf 40225, Germany
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg 79085, Germany. Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Lopes R, Soares R, Coelho R, Figueiredo-Braga M. Angiogenesis in the pathophysiology of schizophrenia — A comprehensive review and a conceptual hypothesis. Life Sci 2015; 128:79-93. [DOI: 10.1016/j.lfs.2015.02.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/27/2015] [Accepted: 02/12/2015] [Indexed: 01/11/2023]
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Telese F, Ma Q, Perez PM, Notani D, Oh S, Li W, Comoletti D, Ohgi KA, Taylor H, Rosenfeld MG. LRP8-Reelin-Regulated Neuronal Enhancer Signature Underlying Learning and Memory Formation. Neuron 2015; 86:696-710. [PMID: 25892301 DOI: 10.1016/j.neuron.2015.03.033] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/11/2015] [Accepted: 03/13/2015] [Indexed: 11/16/2022]
Abstract
One of the exceptional properties of the brain is its ability to acquire new knowledge through learning and to store that information through memory. The epigenetic mechanisms linking changes in neuronal transcriptional programs to behavioral plasticity remain largely unknown. Here, we identify the epigenetic signature of the neuronal enhancers required for transcriptional regulation of synaptic plasticity genes during memory formation, linking this to Reelin signaling. The binding of Reelin to its receptor, LRP8, triggers activation of this cohort of LRP8-Reelin-regulated neuronal (LRN) enhancers that serve as the ultimate convergence point of a novel synapse-to-nucleus pathway. Reelin simultaneously regulates NMDA-receptor transmission, which reciprocally permits the required γ-secretase-dependent cleavage of LRP8, revealing an unprecedented role for its intracellular domain in the regulation of synaptically generated signals. These results uncover an in vivo enhancer code serving as a critical molecular component of cognition and relevant to psychiatric disorders linked to defects in Reelin signaling.
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Affiliation(s)
- Francesca Telese
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Qi Ma
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Bioinformatis and System Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Patricia Montilla Perez
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dimple Notani
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Soohwan Oh
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wenbo Li
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Davide Comoletti
- Child Health Institute of New Jersey and Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA
| | - Kenneth A Ohgi
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Havilah Taylor
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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Abstract
Members of the low-density lipoprotein (LDL) receptor gene family have a diverse set of biological functions that transcend lipid metabolism. Lipoprotein receptors have broad effects in both the developing and adult brain and participate in synapse development, cargo trafficking, and signal transduction. In addition, several family members play key roles in Alzheimer's disease (AD) pathogenesis and neurodegeneration. This Review summarizes our current understanding of the role lipoprotein receptors play in CNS function and AD pathology, with a special emphasis on amyloid-independent roles in endocytosis and synaptic dysfunction.
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Burrell TC, Divekar SD, Weeber EJ, Rebeck GW. Fyn tyrosine kinase increases Apolipoprotein E Receptor 2 levels and phosphorylation. PLoS One 2014; 9:e110845. [PMID: 25340851 PMCID: PMC4207760 DOI: 10.1371/journal.pone.0110845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/25/2014] [Indexed: 11/27/2022] Open
Abstract
Apolipoprotein E Receptor 2 (ApoER2) and the tyrosine kinase Fyn are both members of the Reelin pathway, a signaling pathway essential for the laminar formation of the cortex during development and proper dendritic spine density and long-term potential (LTP) in the adult brain. In the presence of extracellular Reelin, ApoER2 binds the intracellular protein Dab1, an adaptor protein that is phosphorylated by Fyn. However, direct interactions between ApoER2 and Fyn are not well defined. Here, we show that total levels of ApoER2 and surface levels of ApoER2 are increased by active Fyn. Via a separate mechanism, ApoER2 is also phosphorylated by Fyn, an event that peaks in the postnatal cortex at day 5 and can occur at multiple ApoER2 tyrosine residues. Dab1 is also involved in this phosphorylation, promoting the phosphorylation of ApoER2 by Fyn when it is itself phosphorylated. These results elucidate some of the intracellular mechanisms that give rise to a functional Reelin pathway.
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Affiliation(s)
- Teal C. Burrell
- Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Shailaja D. Divekar
- Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Edwin J. Weeber
- Department of Molecular Pharmacology and Physiology, University of South Florida Health Byrd Alzheimer’s Institute, University of South Florida, Tampa, Florida, United States of America
| | - G. William Rebeck
- Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia, United States of America
- * E-mail:
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79
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Larios JA, Jausoro I, Benitez ML, Bronfman FC, Marzolo MP. Neurotrophins regulate ApoER2 proteolysis through activation of the Trk signaling pathway. BMC Neurosci 2014; 15:108. [PMID: 25233900 PMCID: PMC4177048 DOI: 10.1186/1471-2202-15-108] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 09/15/2014] [Indexed: 12/27/2022] Open
Abstract
Background ApoER2 and the neurotrophin receptors Trk and p75NTR are expressed in the CNS and regulate key functional aspects of neurons, including development, survival, and neuronal function. It is known that both ApoER2 and p75NTR are processed by metalloproteinases, followed by regulated intramembrane proteolysis. TrkA activation by nerve growth factor (NGF) increases the proteolytic processing of p75NTR mediated by ADAM17. Reelin induces the sheeding of ApoER2 ectodomain depending on metalloproteinase activity. However, it is not known if there is a common regulation mechanism for processing these receptors. Results We found that TrkA activation by NGF in PC12 cells induced ApoER2 processing, which was dependent on TrkA activation and metalloproteinases. NGF-induced ApoER2 proteolysis was independent of mitogen activated protein kinase activity and of phosphatidylinositol-3 kinase activity. In contrast, the basal proteolysis of ApoER2 increased when both kinases were pharmacologically inhibited. The ApoER2 ligand reelin regulated the proteolytic processing of its own receptor but not of p75NTR. Finally, in primary cortical neurons, which express both ApoER2 and TrkB, we found that the proteolysis of ApoER2 was also regulated by brain-derived growth factor (BDNF). Conclusions Our results highlight a novel relationship between neurotrophins and the reelin-ApoER2 system, suggesting that these two pathways might be linked to regulate brain development, neuronal survival, and some pathological conditions.
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Affiliation(s)
| | | | | | | | - Maria-Paz Marzolo
- Departamento de Biología Celular y Molecular, Laboratorio de Tráfico Intracelular y Señalización, Facultad de Ciencias Biológicas, Pontificia Universidad Católica, Alameda 340, Santiago 8320000, Chile.
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80
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Morgan-Smith M, Wu Y, Zhu X, Pringle J, Snider WD. GSK-3 signaling in developing cortical neurons is essential for radial migration and dendritic orientation. eLife 2014; 3:e02663. [PMID: 25073924 PMCID: PMC4109311 DOI: 10.7554/elife.02663] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
GSK-3 is an essential mediator of several signaling pathways that regulate cortical development. We therefore created conditional mouse mutants lacking both GSK-3α and GSK-3β in newly born cortical excitatory neurons. Gsk3-deleted neurons expressing upper layer markers exhibited striking migration failure in all areas of the cortex. Radial migration in hippocampus was similarly affected. In contrast, tangential migration was not grossly impaired after Gsk3 deletion in interneuron precursors. Gsk3-deleted neurons extended axons and developed dendritic arbors. However, the apical dendrite was frequently branched while basal dendrites exhibited abnormal orientation. GSK-3 regulation of migration in neurons was independent of Wnt/β-catenin signaling. Importantly, phosphorylation of the migration mediator, DCX, at ser327, and phosphorylation of the semaphorin signaling mediator, CRMP-2, at Thr514 were markedly decreased. Our data demonstrate that GSK-3 signaling is essential for radial migration and dendritic orientation and suggest that GSK-3 mediates these effects by phosphorylating key microtubule regulatory proteins. DOI:http://dx.doi.org/10.7554/eLife.02663.001 In the brain, one of the most striking features of the cerebral cortex is that its neurons are organized into different layers that are specifically connected to one another and to other regions of the brain. How newly generated neurons find their appropriate layer during the development of the brain is an important question; and, in humans, when this process goes awry, it can often result in seizures and mental retardation. An enzyme called GSK-3 regulates several major signaling pathways important to brain development. The GSK-3 enzyme switches other proteins on or off by adding phosphate groups to them. Morgan-Smith et al. set out to better understand the role of GSK-3 in brain development by deleting the genes for this enzyme specifically in the cerebral cortex of mice. Mice have two genes that encode slightly different forms of the GSK-3 enzyme. Deleting both of these in different groups of neurons during brain development revealed that a major group of neurons need GSK-3 in order to migrate to the correct layer. Specifically, the movement of neurons from where they arise in the central region of the brain to the outermost layer (a process called radial migration) was disrupted when the GSK-3 genes were deleted. Morgan-Smith et al. further found that cortical neurons without GSK-3 were unable to develop the shape needed to undertake radial migration because they failed to switch from having many branches to having just two main branches. Additional experiments revealed that these abnormalities did not depend on certain signaling pathways, such as the Wnt-signaling pathway or the PI3K signaling pathway that can control GSK-3 activity. Instead, Morgan-Smith et al. found that two proteins that are normally targeted by the GSK-3 enzyme have fewer phosphate groups than normal in the cortical neurons that did not contain the enzyme: both of these proteins regulate the shape of neurons by interacting with the molecular ‘scaffolding’ within the cell. The GSK-3 enzyme was already known to modify the activities of many other proteins that affect the migration of cells. Thus, the findings of Morgan-Smith et al. suggest that this enzyme may coordinate many of the mechanisms thought to underlie this process during brain development. DOI:http://dx.doi.org/10.7554/eLife.02663.002
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Affiliation(s)
- Meghan Morgan-Smith
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, United States Neurobiology Curriculum, University of North Carolina, Chapel Hill, United States
| | - Yaohong Wu
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, United States
| | - Xiaoqin Zhu
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, United States
| | - Julia Pringle
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, United States
| | - William D Snider
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, United States Neurobiology Curriculum, University of North Carolina, Chapel Hill, United States
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De Filippis B, Romano E, Laviola G. Aberrant Rho GTPases signaling and cognitive dysfunction: in vivo evidence for a compelling molecular relationship. Neurosci Biobehav Rev 2014; 46 Pt 2:285-301. [PMID: 24971827 DOI: 10.1016/j.neubiorev.2014.06.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 05/30/2014] [Accepted: 06/17/2014] [Indexed: 01/11/2023]
Abstract
Rho GTPases are key intracellular signaling molecules that coordinate dynamic changes in the actin cytoskeleton, thereby stimulating a variety of processes, including morphogenesis, migration, neuronal development, cell division and adhesion. Deviations from normal Rho GTPases activation state have been proposed to disrupt cognition and synaptic plasticity. This review focuses on the functional consequences of genetic ablation of upstream and downstream Rho GTPases molecules on cognitive function and neuronal morphology and connectivity. Available information on this issue is described and compared to that gained from mice carrying mutations in the most studied Rho GTPases and from pharmacological in vivo studies in which brain Rho GTPases signaling was modulated. Results from reviewed literature provide definitive evidence of a compelling link between Rho GTPases signaling and cognitive function, thus supporting the notion that Rho GTPases and their downstream effectors may represent important therapeutic targets for disorders associated with cognitive dysfunction.
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Affiliation(s)
- Bianca De Filippis
- Sect. Behavioural Neuroscience, Department of Cell Biology & Neuroscience, Istituto Superiore di Sanità, Roma, Italy.
| | - Emilia Romano
- Sect. Behavioural Neuroscience, Department of Cell Biology & Neuroscience, Istituto Superiore di Sanità, Roma, Italy; Bambino Gesù, Children Hospital, IRCCS, Roma, Italy
| | - Giovanni Laviola
- Sect. Behavioural Neuroscience, Department of Cell Biology & Neuroscience, Istituto Superiore di Sanità, Roma, Italy
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82
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Lee GH, Chhangawala Z, von Daake S, Savas JN, Yates JR, Comoletti D, D'Arcangelo G. Reelin induces Erk1/2 signaling in cortical neurons through a non-canonical pathway. J Biol Chem 2014; 289:20307-17. [PMID: 24876378 DOI: 10.1074/jbc.m114.576249] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Reelin is an extracellular protein that controls many aspects of pre- and postnatal brain development and function. The molecular mechanisms that mediate postnatal activities of Reelin are not well understood. Here, we first set out to express and purify the full length Reelin protein and a biologically active central fragment. Second, we investigated in detail the signal transduction mechanisms elicited by these purified Reelin proteins in cortical neurons. Unexpectedly, we discovered that the full-length Reelin moiety, but not the central fragment, is capable of activating Erk1/2 signaling, leading to increased p90RSK phosphorylation and the induction of immediate-early gene expression. Remarkably, Erk1/2 activation is not mediated by the canonical signal transduction pathway, involving ApoER2/VLDLR and Dab1, that mediates other functions of Reelin in early brain development. The activation of Erk1/2 signaling likely contributes to the modulation of neuronal maturation and synaptic plasticity by Reelin in the postnatal and adult brain.
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Affiliation(s)
- Gum Hwa Lee
- From the Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854
| | - Zinal Chhangawala
- the Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, and
| | - Sventja von Daake
- the Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, and
| | - Jeffrey N Savas
- the Department of Chemical Physiology and Molecular and Cellular Neurobiology, The Scripps Research Institute, La Jolla, California 92037
| | - John R Yates
- the Department of Chemical Physiology and Molecular and Cellular Neurobiology, The Scripps Research Institute, La Jolla, California 92037
| | - Davide Comoletti
- the Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, and
| | - Gabriella D'Arcangelo
- From the Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854,
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83
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Waltmann MD, Basford JE, Konaniah ES, Weintraub NL, Hui DY. Apolipoprotein E receptor-2 deficiency enhances macrophage susceptibility to lipid accumulation and cell death to augment atherosclerotic plaque progression and necrosis. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1395-405. [PMID: 24840660 DOI: 10.1016/j.bbadis.2014.05.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 01/29/2023]
Abstract
Genome-wide association studies have linked LRP8 polymorphisms to premature coronary artery disease and myocardial infarction in humans. However, the mechanisms by which dysfunctions of apolipoprotein E receptor-2 (apoER2), the protein encoded by LRP8 gene, influence atherosclerosis have not been elucidated completely. The current study focused on the role of apoER2 in macrophages, a cell type that plays an important role in atherosclerosis. Results showed that apoER2-deficient mouse macrophages accumulated more lipids and were more susceptible to oxidized LDL (oxLDL)-induced death compared to control cells. Consistent with these findings, apoER2 deficient macrophages also displayed defective serum-induced Akt activation and higher levels of the pro-apoptotic protein phosphorylated p53. Furthermore, the expression and activation of peroxisome proliferator-activated receptor γ (PPARγ) were increased in apoER2-deficient macrophages. Deficiency of apoER2 in hypercholesterolemic LDL receptor-null mice (Lrp8(-/-)Ldlr(-/-) mice) also resulted in accelerated atherosclerosis with more complex lesions and extensive lesion necrosis compared to Lrp8(+/+)Ldlr(-/-) mice. The atherosclerotic plaques of Lrp8(-/-)Ldlr(-/-) mice displayed significantly higher levels of p53-positive macrophages, indicating that the apoER2-deficient macrophages contribute to the accelerated atherosclerotic lesion necrosis observed in these animals. Taken together, this study indicates that apoER2 in macrophages limits PPARγ expression and protects against oxLDL-induced cell death. Thus, abnormal apoER2 functions in macrophages may at least in part contribute to the premature coronary artery disease and myocardial infarction in humans with LRP8 polymorphisms. Moreover, the elevated PPARγ expression in apoER2-deficient macrophages suggests that LRP8 polymorphism may be a genetic modifier of cardiovascular risk with PPARγ therapy.
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Affiliation(s)
- Meaghan D Waltmann
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Joshua E Basford
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Eddy S Konaniah
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Neal L Weintraub
- Department of Internal Medicine, Division of Cardiovascular Disease, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - David Y Hui
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH USA.
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84
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Sotelo P, Farfán P, Benitez ML, Bu G, Marzolo MP. Sorting nexin 17 regulates ApoER2 recycling and reelin signaling. PLoS One 2014; 9:e93672. [PMID: 24705369 PMCID: PMC3976305 DOI: 10.1371/journal.pone.0093672] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 03/10/2014] [Indexed: 11/30/2022] Open
Abstract
ApoER2 is a member of the low density-lipoprotein receptor (LDL-R) family. As a receptor for reelin, ApoER2 participates in neuronal migration during development as well as synaptic plasticity and survival in the adult brain. A previous yeast two-hybrid screen showed that ApoER2 is a binding partner of sorting nexin 17 (SNX17) - a cytosolic adaptor protein that regulates the trafficking of several membrane proteins in the endosomal pathway, including LRP1, P-selectin and integrins. However, no further studies have been performed to investigate the role of SNX17 in ApoER2 trafficking and function. In this study, we present evidence based on GST pull-down and inmunoprecipitation assays that the cytoplasmic NPxY endocytosis motif of ApoER2 interacts with the FERM domain of SNX17. SNX17 stimulates ApoER2 recycling in different cell lines including neurons without affecting its endocytic rate and also facilitates the transport of ApoER2 from the early endosomes to the recycling endosomes. The reduction of SNX17 was associated with accumulation of an ApoER2 carboxy-terminal fragment (CTF). In addition, in SNX17 knockdown cells, constitutive ApoER2 degradation was not modified, whereas reelin-induced ApoER2 degradation was increased, implying that SNX17 is a regulator of the receptor's half-life. Finally, in SNX17 silenced hippocampal and cortical neurons, we underscored a positive role of this endosomal protein in the development of the dendritic tree and reelin signaling. Overall, these results establish the role of SNX17 in ApoER2 trafficking and function and aid in identifying new links between endocytic trafficking and receptor signaling.
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Affiliation(s)
- Pablo Sotelo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Millenium Nucleus for Renerative Biology (MINREB), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pamela Farfán
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Millenium Nucleus for Renerative Biology (MINREB), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María Luisa Benitez
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Millenium Nucleus for Renerative Biology (MINREB), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
| | - María-Paz Marzolo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Millenium Nucleus for Renerative Biology (MINREB), Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
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85
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Moon HM, Wynshaw-Boris A. Cytoskeleton in action: lissencephaly, a neuronal migration disorder. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2014; 2:229-45. [PMID: 23495356 DOI: 10.1002/wdev.67] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
During neocortical development, the extensive migratory movements of neurons from their place of birth to their final location are essential for the coordinated wiring of synaptic circuits and proper neurological function. Failure or delay in neuronal migration causes severe abnormalities in cortical layering, which consequently results in human lissencephaly ('smooth brain'), a neuronal migration disorder. The brains of lissencephaly patients have less-convoluted gyri in the cerebral cortex with impaired cortical lamination of neurons. Since microtubule (MT) and actin-associated proteins play important functions in regulating the dynamics of MT and actin cytoskeletons during neuronal migration, genetic mutations or deletions of crucial genes involved in cytoskeletal processes lead to lissencephaly in human and neuronal migration defects in mouse. During neuronal migration, MT organization and transport are controlled by platelet-activating factor acetylhydrolase isoform 1b regulatory subunit 1 (PAFAH1B1, formerly known as LIS1, Lissencephaly-1), doublecortin (DCX), YWHAE, and tubulin. Actin stress fibers are modulated by PAFAH1B1 (LIS1), DCX, RELN, and VLDLR (very low-density lipoprotein receptor)/LRP8 (low-density lipoprotein-related receptor 8, formerly known as APOER2). There are several important levels of crosstalk between these two cytoskeletal systems to establish accurate cortical patterning in development. The recent understanding of the protein networks that govern neuronal migration by regulating cytoskeletal dynamics, from human and mouse genetics as well as molecular and cellular analyses, provides new insights on neuronal migration disorders and may help us devise novel therapeutic strategies for such brain malformations.
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86
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Eresheim C, Leeb C, Buchegger P, Nimpf J. Signaling by the extracellular matrix protein Reelin promotes granulosa cell proliferation in the chicken follicle. J Biol Chem 2014; 289:10182-91. [PMID: 24573679 DOI: 10.1074/jbc.m113.533489] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Chicken oocytes develop in follicles and reach an enormous size because of a massive uptake of yolk precursors such as very low density lipoprotein and vitellogenin. Oocyte growth is supported by theca cells and granulosa cells, which establish dynamic and highly organized cell layers surrounding the oocyte. The signaling processes orchestrating the development of these layered structures are largely unknown. Here we demonstrate that the Reelin pathway, which determines the development of layered neuronal structures in the brain, is also active in chicken follicles. Reelin, which is expressed in theca cells, triggers a signal in granulosa cells via apolipoprotein E receptor 2 and the very low density lipoprotein receptor, resulting in the phosphorylation of disabled-1 and consecutive activation of the phosphatidylinositol 3-kinase/Akt pathway. This signaling pathway supports the proliferation of differentiated granulosa cells to keep up with the demand of cells to cover the rapidly increasing surface of the giant germ cell.
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Affiliation(s)
- Christine Eresheim
- From the Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
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87
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Reelin in the Years: Controlling Neuronal Migration and Maturation in the Mammalian Brain. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/597395] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The extracellular protein Reelin was initially identified as an essential factor in the control of neuronal migration and layer formation in the developing mammalian brain. In the years following its discovery, however, it became clear that Reelin is a multifunctional protein that controls not only the positioning of neurons in the developing brain, but also their growth, maturation, and synaptic activity in the adult brain. In this review, we will highlight the major discoveries of the biological activities of Reelin and the underlying molecular mechanisms that affect the development and function of the mammalian brain, from embryonic ages to adulthood.
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88
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Lattanzio F, Carboni L, Carretta D, Rimondini R, Candeletti S, Romualdi P. Human apolipoprotein E4 modulates the expression of Pin1, Sirtuin 1, and Presenilin 1 in brain regions of targeted replacement apoE mice. Neuroscience 2014; 256:360-9. [DOI: 10.1016/j.neuroscience.2013.10.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/09/2013] [Indexed: 01/06/2023]
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Neural ECM molecules in synaptic plasticity, learning, and memory. PROGRESS IN BRAIN RESEARCH 2014; 214:53-80. [DOI: 10.1016/b978-0-444-63486-3.00003-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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90
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Kerrisk ME, Cingolani LA, Koleske AJ. ECM receptors in neuronal structure, synaptic plasticity, and behavior. PROGRESS IN BRAIN RESEARCH 2014; 214:101-31. [PMID: 25410355 DOI: 10.1016/b978-0-444-63486-3.00005-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During central nervous system development, extracellular matrix (ECM) receptors and their ligands play key roles as guidance molecules, informing neurons where and when to send axonal and dendritic projections, establish connections, and form synapses between pre- and postsynaptic cells. Once stable synapses are formed, many ECM receptors transition in function to control the maintenance of stable connections between neurons and regulate synaptic plasticity. These receptors bind to and are activated by ECM ligands. In turn, ECM receptor activation modulates downstream signaling cascades that control cytoskeletal dynamics and synaptic activity to regulate neuronal structure and function and thereby impact animal behavior. The activities of cell adhesion receptors that mediate interactions between pre- and postsynaptic partners are also strongly influenced by ECM composition. This chapter highlights a number of ECM receptors, their roles in the control of synapse structure and function, and the impact of these receptors on synaptic plasticity and animal behavior.
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Affiliation(s)
- Meghan E Kerrisk
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Lorenzo A Cingolani
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Anthony J Koleske
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Department of Neurobiology, Yale University, New Haven, CT, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University, New Haven, CT, USA.
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91
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Leeb C, Eresheim C, Nimpf J. Clusterin is a ligand for apolipoprotein E receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR) and signals via the Reelin-signaling pathway. J Biol Chem 2013; 289:4161-72. [PMID: 24381170 DOI: 10.1074/jbc.m113.529271] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clusterin, also known as apolipoprotein J, is a multifunctional glycoprotein with the capacity to interact with a wide range of molecules. Although clusterin has been implicated in a broad spectrum of physiological and pathological processes, such as Alzheimer disease or cancer, its precise functions remain elusive. Here we report, that clusterin binds to apolipoprotein E receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR) and is internalized by cells expressing either one of these receptors. Binding of clusterin to these receptors triggers a Reelin-like signal in cells expressing disabled-1 (Dab1). It induces phosphorylation of Dab1, which leads to activation of PI3K/Akt and n-cofilin. Cell proliferation and neuroblast chain formation in subventricular zone (SVZ) explants are compromised when clusterin, which is present in the subventricular zone, is blocked in vitro. These data suggest that in the subventricular zone where Reelin is not present but ApoER2, VLDLR, and Dab1, clusterin might be involved in maintaining neurogenesis in vivo.
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Affiliation(s)
- Christian Leeb
- From the Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University Vienna, 1030 Vienna, Austria
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92
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Balmaceda V, Cuchillo-Ibáñez I, Pujadas L, García-Ayllón MS, Saura CA, Nimpf J, Soriano E, Sáez-Valero J. ApoER2 processing by presenilin-1 modulates reelin expression. FASEB J 2013; 28:1543-54. [PMID: 24344333 DOI: 10.1096/fj.13-239350] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The reelin signaling protein and its downstream components have been associated with synaptic plasticity and neurotransmission. The reelin signaling pathway begins with the binding of reelin to the transmembrane lipoprotein receptor apolipoprotein E receptor 2 (ApoER2), which in turns induces the sequential cleavage of ApoER2 by the sequential action of α- and γ-secretases. Using conditional-knockout mice of the catalytic component of the γ-secretase complex, presenilin 1 (PS1), we demonstrated increased brain ApoER2 and reelin protein and transcript levels, with no changes in the number of reelin-positive cells. Using the human SH-SY5Y neuroblastoma cell line, we showed that ApoER2 processing occurs in the presence of PS1, producing an intracellular ApoER2 C-terminal fragment. In addition, the pharmacologic inhibition of γ-secretase in SH-SY5Y cells led to increased reelin levels. Overexpression of ApoER2 decreased reelin mRNA levels in these cells. A luciferase reporter gene assay and nuclear fractionation confirmed that increased amounts of intracellular fragment of ApoER2 suppressed reelin expression at a transcriptional level. Chromatin immunoprecipitation experiments corroborated that the intracellular fragment of ApoER2 bound to the RELN promoter region. Our study suggests that PS1/γ-secretase-dependent processing of the reelin receptor ApoER2 inhibits reelin expression and may regulate its signaling.
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Affiliation(s)
- Valeria Balmaceda
- 1Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Av. Ramón y Cajal s/n, E-03550 Sant Joan d'Alacant, Spain.
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Abstract
Disabled-1 (Dab1) is an adaptor protein that is an obligate effector of the Reelin signaling pathway, and is critical for neuronal migration and dendrite outgrowth during development. Components of the Reelin pathway are highly expressed during development, but also continue to be expressed in the adult brain. Here we investigated in detail the expression pattern of Dab1 in the postnatal and adult forebrain, and determined that it is expressed in excitatory as well as inhibitory neurons. Dab1 was found to be localized in different cellular compartments, including the soma, dendrites, presynaptic and postsynaptic structures. Mice that are deficient in Dab1, Reelin, or the Reelin receptors ApoER2 and VLDLR exhibit severely perturbed brain cytoarchitecture, limiting the utility of these mice for investigating the role of this signaling pathway in the adult brain. In this study, we developed an adult forebrain-specific and excitatory neuron-specific conditional knock-out mouse line, and demonstrated that Dab1 is a critical regulator of synaptic function and hippocampal-dependent associative and spatial learning. These dramatic abnormalities were accompanied by a reduction in dendritic spine size, and defects in basal and plasticity-induced Akt and ERK1/2 signaling. Deletion of Dab1 led to no obvious changes in neuronal positioning, dendrite morphology, spine density, or synaptic composition. Collectively, these data conclusively demonstrate an important role for Reelin-Dab1 signaling in the adult forebrain, and underscore the importance of this pathway in learning and memory.
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94
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Matsuki T, Chen J, Howell BW. Acute inactivation of the serine-threonine kinase Stk25 disrupts neuronal migration. Neural Dev 2013; 8:21. [PMID: 24225308 PMCID: PMC3874637 DOI: 10.1186/1749-8104-8-21] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 11/05/2013] [Indexed: 11/16/2022] Open
Abstract
Background Neuronal migration involves the directional migration of immature neurons. During much of the migration period these neurons are polarized with defined leading and trailing processes. Stk25 has been shown to bind to the LKB1 activator STRAD and regulate neuronal polarization and dendritogenesis in an opposing manner to Reelin-Dab1 signaling. It is not known, however, whether Stk25 controls neuronal migration, a key developmental process regulated by Reelin-Dab1 signal transduction. Findings Here we find that while constitutive Stk25 deficiency does not lead to neuronal phenotypes, acute reduction by either Cre-mediated gene inactivation or by knockdown causes a developmental neuronal migration error. Furthermore, we find that knockdown of LKB1, STRAD and GM130, molecules that have previously been implicated with Stk25, causes similar aberrations in neuronal migration. Conclusions Loss of Stk25 function early in development likely leads to functional compensation for its roles in neuronal development. Stk25 regulates neuronal positioning, possibly as part of the LKB1-STRAD-Stk25-GM130 pathway that was previously shown to be important for neuronal polarization.
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Affiliation(s)
| | | | - Brian W Howell
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 750 E, Adams St, Syracuse, NY 13210, USA.
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95
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Bal M, Leitz J, Reese AL, Ramirez DMO, Durakoglugil M, Herz J, Monteggia LM, Kavalali ET. Reelin mobilizes a VAMP7-dependent synaptic vesicle pool and selectively augments spontaneous neurotransmission. Neuron 2013; 80:934-46. [PMID: 24210904 DOI: 10.1016/j.neuron.2013.08.024] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2013] [Indexed: 02/07/2023]
Abstract
Reelin is a glycoprotein that is critical for proper layering of neocortex during development as well as dynamic regulation of glutamatergic postsynaptic signaling in mature synapses. Here, we show that Reelin also acts presynaptically, resulting in robust rapid enhancement of spontaneous neurotransmitter release without affecting properties of evoked neurotransmission. This effect of Reelin requires a modest but significant increase in presynaptic Ca(2+) initiated via ApoER2 signaling. The specificity of Reelin action on spontaneous neurotransmitter release is encoded at the level of vesicular SNARE machinery as it requires VAMP7 and SNAP-25 but not synaptobrevin2, VAMP4, or vti1a. These results uncover a presynaptic regulatory pathway that utilizes the heterogeneity of synaptic vesicle-associated SNAREs and selectively augments action potential-independent neurotransmission.
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Affiliation(s)
- Manjot Bal
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
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96
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Interdigital cell death in the embryonic limb is associated with depletion of Reelin in the extracellular matrix. Cell Death Dis 2013; 4:e800. [PMID: 24030152 PMCID: PMC3789180 DOI: 10.1038/cddis.2013.322] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/08/2013] [Accepted: 07/30/2013] [Indexed: 01/01/2023]
Abstract
Interdigital cell death is a physiological regression process responsible for sculpturing the digits in the embryonic vertebrate limb. Changes in the intensity of this degenerative process account for the different patterns of interdigital webbing among vertebrate species. Here, we show that Reelin is present in the extracellular matrix of the interdigital mesoderm of chick and mouse embryos during the developmental stages of digit formation. Reelin is a large extracellular glycoprotein which has important functions in the developing nervous system, including neuronal survival; however, the significance of Reelin in other systems has received very little attention. We show that reelin expression becomes intensely downregulated in both the chick and mouse interdigits preceding the establishment of the areas of interdigital cell death. Furthermore, fibroblast growth factors, which are cell survival signals for the interdigital mesoderm, intensely upregulated reelin expression, while BMPs, which are proapototic signals, downregulate its expression in the interdigit. Gene silencing experiments of reelin gene or its intracellular effector Dab-1 confirmed the implication of Reelin signaling as a survival factor for the limb undifferentiated mesoderm. We found that Reelin activates canonical survival pathways in the limb mesoderm involving protein kinase B and focal adhesion kinase. Our findings support that Reelin plays a role in interdigital cell death, and suggests that anoikis (apoptosis secondary to loss of cell adhesion) may be involved in this process.
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97
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Holtzman DM, Herz J, Bu G. Apolipoprotein E and apolipoprotein E receptors: normal biology and roles in Alzheimer disease. Cold Spring Harb Perspect Med 2013; 2:a006312. [PMID: 22393530 DOI: 10.1101/cshperspect.a006312] [Citation(s) in RCA: 570] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Apolipoprotein E (APOE) genotype is the major genetic risk factor for Alzheimer disease (AD); the ε4 allele increases risk and the ε2 allele is protective. In the central nervous system (CNS), apoE is produced by glial cells, is present in high-density-like lipoproteins, interacts with several receptors that are members of the low-density lipoprotein receptor (LDLR) family, and is a protein that binds to the amyloid-β (Aβ) peptide. There are a variety of mechanisms by which apoE isoform may influence risk for AD. There is substantial evidence that differential effects of apoE isoform on AD risk are influenced by the ability of apoE to affect Aβ aggregation and clearance in the brain. Other mechanisms are also likely to play a role in the ability of apoE to influence CNS function as well as AD, including effects on synaptic plasticity, cell signaling, lipid transport and metabolism, and neuroinflammation. ApoE receptors, including LDLRs, Apoer2, very low-density lipoprotein receptors (VLDLRs), and lipoprotein receptor-related protein 1 (LRP1) appear to influence both the CNS effects of apoE as well as Aβ metabolism and toxicity. Therapeutic strategies based on apoE and apoE receptors may include influencing apoE/Aβ interactions, apoE structure, apoE lipidation, LDLR receptor family member function, and signaling. Understanding the normal and disease-related biology connecting apoE, apoE receptors, and AD is likely to provide novel insights into AD pathogenesis and treatment.
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Affiliation(s)
- David M Holtzman
- Department of Neurology, Alzheimer's Disease Research Center, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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98
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Kanaan NM, Pigino GF, Brady ST, Lazarov O, Binder LI, Morfini GA. Axonal degeneration in Alzheimer's disease: when signaling abnormalities meet the axonal transport system. Exp Neurol 2013; 246:44-53. [PMID: 22721767 PMCID: PMC3465504 DOI: 10.1016/j.expneurol.2012.06.003] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 04/17/2012] [Accepted: 06/09/2012] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is characterized by progressive, age-dependent degeneration of neurons in the central nervous system. A large body of evidence indicates that neurons affected in AD follow a dying-back pattern of degeneration, where abnormalities in synaptic function and axonal connectivity long precede somatic cell death. Mechanisms underlying dying-back degeneration of neurons in AD remain elusive but several have been proposed, including deficits in fast axonal transport (FAT). Accordingly, genetic evidence linked alterations in FAT to dying-back degeneration of neurons, and FAT defects have been widely documented in various AD models. In light of these findings, we discuss experimental evidence linking several AD-related pathogenic polypeptides to aberrant activation of signaling pathways involved in the phosphoregulation of microtubule-based motor proteins. While each pathway appears to affect FAT in a unique manner, in the context of AD, many of these pathways might work synergistically to compromise the delivery of molecular components critical for the maintenance and function of synapses and axons. Therapeutic approaches aimed at preventing FAT deficits by normalizing the activity of specific protein kinases may help prevent degeneration of vulnerable neurons in AD.
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Affiliation(s)
- Nicholas M Kanaan
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
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99
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Brunne B, Franco S, Bouché E, Herz J, Howell BW, Pahle J, Müller U, May P, Frotscher M, Bock HH. Role of the postnatal radial glial scaffold for the development of the dentate gyrus as revealed by Reelin signaling mutant mice. Glia 2013; 61:1347-63. [PMID: 23828756 DOI: 10.1002/glia.22519] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 03/14/2013] [Accepted: 04/05/2013] [Indexed: 12/11/2022]
Abstract
During dentate gyrus development, the early embryonic radial glial scaffold is replaced by a secondary glial scaffold around birth. In contrast to neocortical and early dentate gyrus radial glial cells, these postnatal glial cells are severely altered with regard to position and morphology in reeler mice lacking the secreted protein Reelin. In this study, we focus on the functional impact of these defects. Most radial glial cells throughout the nervous system serve as scaffolds for migrating neurons and precursor cells for both neurogenesis and gliogenesis. Precursor cell function has been demonstrated for secondary radial glial cells but the exact function of these late glial cells in granule cell migration and positioning is not clear. No data exist concerning the interplay between granule neurons and late radial glial cells during dentate gyrus development. Herein, we show that despite the severe morphological defects in the reeler dentate gyrus, the precursor function of secondary radial glial cells is not impaired during development in reeler mice. In addition, selective ablation of Disabled-1, an intracellular adaptor protein essential for Reelin signaling, in neurons but not in glial cells allowed us to distinguish effects of Reelin signaling on radial glial cells from possible secondary effects based on defective granule cells positioning.
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Affiliation(s)
- Bianka Brunne
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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100
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Notter T, Knuesel I. Reelin immunoreactivity in neuritic varicosities in the human hippocampal formation of non-demented subjects and Alzheimer's disease patients. Acta Neuropathol Commun 2013; 1:27. [PMID: 24252415 PMCID: PMC3893416 DOI: 10.1186/2051-5960-1-27] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/10/2013] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Reelin and its downstream signaling members are important modulators of actin and microtubule cytoskeleton dynamics, a fundamental prerequisite for proper neurodevelopment and adult neuronal functions. Reductions in Reelin levels have been suggested to contribute to Alzheimer's disease (AD) pathophysiology. We have previously reported an age-related reduction in Reelin levels and its accumulation in neuritic varicosities along the olfactory-limbic tracts, which correlated with cognitive impairments in aged mice. Here, we aimed to investigate whether a similar Reelin-associated neuropathology is observed in the aged human hippocampus and whether it correlated with dementia status. RESULTS Our immunohistochemical stainings revealed the presence of N- and C-terminus-containing Reelin fragments in corpora amylacea (CAm), aging-associated spherical deposits. The density of these deposits was increased in the molecular layer of the subiculum of AD compared to non-demented individuals. Despite the limitation of a small sample size, our evaluation of several neuronal and glial markers indicates that the presence of Reelin in CAm might be related to aging-associated impairments in neuronal transport leading to accumulation of organelles and protein metabolites in neuritic varicosities, as previously suggested by the findings and discussions in rodents and primates. CONCLUSIONS Our results indicate that aging- and disease-associated changes in Reelin levels and proteolytic processing might play a role in the formation of CAm by altering cytoskeletal dynamics. However, its presence may also be an indicator of a degenerative state of neuritic compartments.
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